I have a big version-controlled directory hosting a lot of half-independent bodies of work. I want to consider them all as projects for projectile.

So I added an empty `.projectile` file in each of them, with the idea that projectile would pick that up instead of the `.git` above.

So the situation is like this

 ~/main-directory/
 -> .git
 -> project1/
 -> .projectile
 -> file1
 -> file2
 -> project2/
 -> .projectile
 -> file1
 -> file2

But if I open `~/main-directory/project2/file1` and call `projectile-add-known-project`, it considers the whole `main-directory` as one project. In particular, completion matches files with the same name in all subdirectories...

I have tried `(setq projectile-project-root-files-bottom-up (delete ".projectile" projectile-project-root-files-bottom-up))`, but it did not help.

Is there a simple way of telling projectile that the `main-directory` is not to be considered a project?